This invention relates to speech recognition in general and, more particularly, provides a way of providing remotely-accessible automatic speech recognition services via a packet network.
Techniques for accomplishing automatic speech recognition (ASR) are well known. Among known ASR techniques are those that use grammars. A grammar is a representation of the language or phrases expected to be used or spoken in a given context. In one sense, then, ASR grammars typically constrain the speech recognizer to a vocabulary that is a subset of the universe of potentially-spoken words; and grammars may include sub-grammars. An ASR grammar rule can then be used to represent the set of xe2x80x9cphrasesxe2x80x9d or combinations of words from one or more grammars or subgrammars that may be expected in a given context. xe2x80x9cGrammarxe2x80x9d may also refer generally to a statistical language model (where a model represents phrases), such as those used in language understanding systems.
Products and services that utilize some form of automatic speech recognition (xe2x80x9cASRxe2x80x9d) methodology have been recently introduced commercially. For example, ATandT has developed a grammar-based ASR engine called WATSON that enables development of complex ASR services. Desirable attributes of complex ASR services that would utilize such ASR technology include high accuracy in recognition; robustness to enable recognition where speakers have differing accents or dialects, and/or in the presence of background noise; ability to handle large vocabularies; and natural language understanding. In order to achieve these attributes for complex ASR services, ASR techniques and engines typically require computer-based systems having significant processing capability in order to achieve the desired speech recognition capability. Processing capability as used herein refers to processor speed, memory, disk space, as well as access to application databases. Such requirements have restricted the development of complex ASR services that are available at one""s desktop, because the processing requirements exceed the capabilities of most desktop systems, which are typically based on personal computer (PC) technology.
Packet networks are general-purpose data networks which are well-suited for sending stored data of various types, including speech or audio. The Internet, the largest and most renowned of the existing packet networks, connects over 4 million computers in some 140 countries. The Internet""s global and exponential growth is common knowledge today.
Typically, one accesses a packet network, such as the Internet, through a client software program executing on a computer, such as a PC, and so packet networks are inherently client/server oriented. One way of accessing information over a packet network is through use of a Web browser (such as the Netscape Navigator, available from Netscape Communications, Inc., and the Internet Explorer, available from Microsoft Corp.) which enables a client to interact with Web servers. Web servers and the information available therein are typically identified and addressed through a Uniform Resource Locator (URL)-compatible address. URL addressing is widely used in Internet and intranet applications and is well known to those skilled in the art (an xe2x80x9cintranetxe2x80x9d is a packet network modeled in functionality based upon the Internet and is used, e.g., by companies locally or internally).
What is desired is a way of enabling ASR services that may be made available to users at a location, such as at their desktop, that is remote from the system hosting the ASR engine.
A system and method of operating an automatic speech recognition service using a client-server architecture is used to make ASR services accessible at a client location remote from the location of the main ASR engine. In accordance with the present invention, using client-server communications over a packet network, such as the Internet, the ASR server receives a grammar from the client, receives information representing speech from the client, performs speech recognition, and returns information based upon the recognized speech to the client. Alternative embodiments of the present invention include a variety of ways to obtain access to the desired grammar, use of compression or feature extraction as a processing step at the ASR client prior to transferring speech information to the ASR server, staging a dialogue between client and server, and operating a form-filling service.